\begin{figure}[h!]%使用figure环境
    \begin{circuitikz}
        \draw (0, 0) node[op amp](A1){} node {$A_1$};
        \draw (A1.-) to[R=$R_1$,-o] ++(-2, 0) node[left] {$u_i$};
        \draw (A1.+) to[R=$R_2$] ++(0, -2) node[ground](GND){};
        \draw (A1.-) -- ++(0,1) coordinate(tmp) to[C=$C$] (tmp -| A1.out) -- (A1.out);
        \draw (A1.out) to[short,-o] ++(2,0) node[right] {$u_o$};
    \end{circuitikz}
    \caption{积分运算电路}%添加标题
\end{figure}




